Jhan, I was looking for an answer to this same question today. I didn't get the answer from Gourmet Tails, but I think I have it figured out. On the ones I bought from our store, there is a sticker on the side of the container. Mine read "BEST302O" with "1029215" under it. I have others with "BEST045F" with 021415" under it.

The top line is a Julian date. It signifies day 302 (October 29) and the O is the first letter of the month that date is in. In my other example, it's Julian date 045, which is February 14. So I have an F after the Julian date digits.

The number on the bottom roughly correlates to the normal calendar date. In my first example, for some reason, there is an extra digit 2 in the number. If you ignore that extra 2, it reads 102915. I have a November container that has that extra 2 in the date.

So the sticker on the side has both Julian and regular calendar date of the "best by" date. That wouldn't mean the treats should be thrown out that next day, but they should be used pretty soon after that.